Rory McIlroy (pictured) and Phil Mickelson are the only top-10 players in the field at the Wells Fargo Championship.

CHARLOTTE, N.C. — Quail Hollow had the energy of a major when it first returned to the PGA Tour schedule 11 years ago.

Now it’s gearing up to host the real thing — the 2017 PGA Championship — with new grass on the greens and an exciting renovation of its daunting, three-hole closing stretch known as the “Green Mile.”

“It’s a beautiful test of golf,” Phil Mickelson said Wednesday. “There is not much you can do to this tournament to make it better.”

All that’s lacking is a major field for the Wells Fargo Championship.

Mickelson and Rory McIlroy are on opposite sides of the draw when the tournament gets started Thursday, and any event would love to have those two stars. But they are the only players from the top 10, and while that’s one more than last year, it’s a mighty change from the time when Quail Hollow once attracted everyone from the top 10, and 27 of the top 30 in the world.

Some of that is scheduling.

There has been only a two-week gap between Augusta National and Quail Hollow the last two years, instead of a three-week break. That’s a product of how the calendar falls, and in golf, the calendar is built around the Masters being held the first full week in April. Masters champion Bubba Watson won’t return until next week.

Some of it has to do with injuries. Tiger Woods is a regular at Quail Hollow (and a past champion), but he is recovering from back surgery. Jason Day is sitting this week out to let his injured left thumb fully heal.

More players are involved in corporate programs with RBC (Hilton Head) and Zurich (New Orleans), and The Players Championship with its $10 million purse is next week. Others, such as Jordan Spieth, have back-to-back events in their native Texas after The Players.

And perhaps there is the memory of last year, when a combination of factors led to the bent greens having large patches of no grass. Nine players withdrew the week of the tournament. Even with new greens that roll beautifully, it usually takes at least a year for the grass to fully settle.

“I think some players probably wanted to wait a year and maybe play someplace they haven’t played,” Mickelson said. “But I was so excited to come and see it, because I just knew that they were going to get it right, and they sure did. It’s really fun to play.”

For now, Mickelson and McIlroy are eager to embark on what amounts to the second stage of the season. The Masters is over. The U.S. Open looms just over a month away. And it starts with a tournament that keeps trying to get better even when it was great.

The greens are now Bermuda grass and rolling beautifully, though typical of new greens, they are firm with bounce. Some of the sharp edges on the putting greens have been softened, allowing for a variety of shots into the greens.

The slopes aren’t nearly as severe on Nos. 12 and 18. The latter was so tough one year that Mickelson had a birdie putt and told his caddie not to tend the flagstick because Mickelson felt playing 6 feet away from the cup was his best chance to make par.

But the biggest change is found on the 16th hole.

Off the tee, the fairway now runs left of a large oak tree instead of to the right of it. The lake is well below the left side of the fairway, although a wild hook by a power player could bring water into play. The green has been moved 80 yards to the left with water along the left side and round to the back.

“Before that it was a tough hole,” Webb Simpson said. “Now it’s a really tough hole.”

The tee on the 221-yard 17th hole has been shifted to the left, allowing for a more straightforward shot over the water to a green that is nearly an island. But it’s a long shot. With the back tee, players had to hit a hybrid or long iron into the green.

“If you play it all the way back, there would be probably 70 percent of all players will bail out right and try and chip or putt it and try and make bogey,” Jonas Blixt said.

And if the 18th wasn’t difficult enough, it was stretched out slightly to 493 yards.

Still, the course looks as pure as it usually does, especially the greens.

“For how new the greens are, I think they’re in fantastic shape, especially after what happened to the greens last year,” McIlroy said.

“It’s obviously a great improvement, and I’m sure they will be looking toward the PGA in `17. They will be perfect.”